Depardieu has joined some of France's wealthiest business figures in Belgium following moves by President Francois Hollande's Socialist government to tax annual incomes above one million euros ($NZ1.6 million) at 75 per cent.

Belgium does not impose a wealth tax and has not had one since 1830.

Its income and inheritance taxes are also lower.

In his letter, Depardieu, who has extensive business interests including wine estates and three Paris restaurants, accused the Socialists of driving France's most talented figures out of the country.

He said he had paid a total of 145 million euros into state coffers over 45 years of working and running businesses in France.

Ayrault's attack came after it emerged that Depardieu had taken up residence in Nechin, a tiny village just over the border in Belgium, which is a favoured spot for wealthy French nationals avoiding tax.

"I find it quite pathetic," Ayrault said. "Everyone loves him as an artist but paying your taxes is an act of solidarity and patriotism."

The affair was seized on by the right-wing UMP party of Hollande's predecessor Nicolas Sarkozy, whose leader Jean-Francois Cope said the president - who famously said he did not "like the rich" - was destroying the country.

"What I regret above all is how the Socialist government is running the country into the ground," Cope said on Monday, denouncing the "tax bludgeoning which is hitting all French citizens."

"He is in the process of taking our country backwards."

France's richest man Bernard Arnault came under fire in September when it emerged that he had applied for Belgian citizenship.

Arnault, the boss of luxury conglomerate LVMH, denied he was seeking to become a tax exile, saying he wanted Belgian nationality "for personal reasons".